Step 1: Understand what +M and -I effects mean. +M (positive mesomeric) effect refers to the ability of a substituent to donate electron density through resonance. -I (negative inductive) effect refers to the ability of a substituent to withdraw electron density due to its electronegativity.
Step 2: Identify the substituent in question, which is -NH2 (amino group).
Step 3: Analyze the +M effect of -NH2. The lone pairs on the nitrogen can donate electron density to the aromatic ring through resonance, which is why it has a +M effect.
Step 4: Analyze the -I effect of -NH2. Nitrogen is more electronegative than carbon, so it pulls electron density away from the carbon atoms, resulting in a -I effect.
Step 5: Conclude that -NH2 has both +M and -I effects because it can donate electrons through resonance and withdraw electrons due to its electronegativity.
